Multiple-step flying-boat.



T To all 'whom it may concern.'

UNITED STATES PATENT onrion GLENN II. CURTISS AND JOHN P. TnnBOx, OFBUFFALO, ANEW YORK, AssIdNns `7`To THE CURTISS MOTOR Co., A CORPORATIONor NEW YORK. y 4,

Beit knownthat'we, GLENN CURTISS and JOHN P.'Txnnox,.citizens oftheUnited States, residing at Buffalo, in the county-of -Erie and State ofNew York, have invented certain new and useful Improvements inMultiple-Step Flying-Boats, of which the following is a specification.,

Our invention relates particularly to that type of craft `which may bebroadly termed hydroplane flying machines. Water flying machinesgenerally are provided with hydroplaning surfaces which enable theml torise quickly to the surface of the water when starting from a stationaryposition and having risen to the surface to skim thereover at very f Theying machines of today are ever .growing larger.L The Original .machineof a simple ponhghSpeed. The invention has particularly to do with theform of this surface as related -to the machine structure as-'a whole.`However, it is capable of adaptation in other and perhaps simplercombinations, such for instance as in a hydroplane boat provided withlighter-than-air supporting means, or in a boat supported byj itsthistype was supported b toon theend surface of w ich was continuous yflat and served as the hydroplane, be-

ing l'setat the correct planin angle with re spect tothe remainder o thestructure.

Later, the flying boat vwas developed. This was larger, longer andmore'seaworthy and its body approximated the form ofa boat hull inshape, the passengers being seated therein, whereas passengers on theOld pon-4 toon type were seated in the aeroplane structure proper. Thebottom of this is provided witha step located approximately verticallybelowthe center of gravity of the structure as a whole, but this stepdefines only a single hydro laning surface, located between itself and te prow ofthe boat, thetail of the boat havin and upwar lient anglewiththe planing surface. -As the craft become still larger, it isnecessary to provide them with-a lural number of hydroplane surfaces deed/ by a multiple number of steps after the fashion of the bottom of thehigh speed-motor boats which have proved so efficient within recentyears.

When it is attempted, however,y to apply v this lconstruction tohydroplaner flying ma- Application led January 13, 1916. Serial No.71,944).

aibottom inclined rearwardly f land. making an especially sa-MULTIPLE-STEP FLYING-BOAT.

specification f Letters Pate'n'tl Patented Apr. Il?, 19117.'

chines,it is found that it is wholly unadapted 1n .the form in vvhich'lthas been heretofore known, for to provide a multiple number of stepsmeans a great elongation ofl the hydroplaning area both forwardv andrearward with Vthe result that rocking 'action necessary 1n operating toleave the water, is

`Wholly destroyed. Therefore, without makmatter 'how many the number ofsteps and how far forward or rearward of the center ofl gravity orcenter of pressure of the structure these steps are extended, themachine can always have its longitudinal ldirection of travel in andover` the water changed by theapplication of the comparatively smallforce necessary to rockihe machine longitudinally pon its convex bottom.Thus longitudinal or fore and 'aft travel of the I center of hydropl anelift with respect to the center of gravity of the machine is `reduced toa minimum, for it is progressively trans- .ferred between a pluralnumber of steps, as

these steps on the rocking succeed each other in position relative tothe center of gravity of the machine. Further, we arrange the convexityof the series of steps in such posi- .tional relation with respect tothe center of gravity of the machine as' a whole that when the craft istravelinghorizontally, the lowermost point of c onvexityliesapproximately vertically below the center offgr Still further, thesteps are'made incre,l frg'ly long and increasinglydeep from the vprowof the boat toward its tail. if

In the accompanyin drawings we have shown the principal em Odiments ofour invention known to usfat the present time but it is, of course,understood that the invention' may be given manyembodimentsf'withoutdeparting from its generic principle.

Figure l shows an embodiment in which the convexity of the bottom isformed as a llO 2 0 the 'tail portion o, as in Flg. 4L makmgsuch anangle with respect to the surface a and 4.0` Vex formationlongitudinally of the boat,

atleast one of said steps being disposed in curvel having its meancenter A'approximately in verticalv alinement with the center of gravityof the machine;

' Fig. 2 shows an embodiment inwhich the co vexity conforms exactly tothe lines ofy a salient angle.

'respects'adjacentl or semi-adjacent hydro- This is true, of course, as

- l planing surfaces of the form -of Fig. l;

4tion 5 Fig. 3 is a diagram showing. the old form of horizontallyarranged multiplel step bottom inserted Ahere for showing the differencebetween that form land our invention Fig. 4 is a viewof an' embodimentsimilar to Figl, sh'owingthe steps not only .in- 15 creasing inheightfrom- .bonT tov stern'. but also surfaces increased in length fofthe steps;

two ste s are used and two hydroplaning su aces, the\one"a and the other6,

b as tobe devoid of hydroplaning func- Fig. esho'wsa sau further-ferm inwhich three steps are provided and three hydro planing surfaces, thecenter step constitut" "ingthe apex of the salient angle formation 1.A,-liydroplane fboat, the bottom of whichat `the keel line isl formedlongitudinallyr on the are of a-curve having its ,cen-4 ter m anapproximately vertical longitudinalplane and is provided with stepsarranged respectivelyfore and aft of the vertical plane of said center.

2A hydroplane boat, the hydroplaning bottom of which at the keel line isconstituted by a series of steps arranged in a conthe vicinity of thepoint of maximum convexity.

3. A hydroplane boat, the hydroplaning bottom of which is provided witha multi- Fig. 5 1s van embodiment in which only formationlongitudinal-lv of the boat, and each step of which 'is longer than 'thepreceding step.

4. A hydroplane boat, the hydroplaning 'bottom of which is vprovidedwith`a multiplaning bottom provided with a multiple number of stepsarranged. at the keel line' in convex formation longitudinally of theboat, the lowermost step being disposed in 4the-vicinityy of a lineprojected vertically through the center of gravity of the machine.'

6. A hyd-ro lane flyingmachine comprising a'hydrop ane'structure, anaerial supporting surface .connecting therewith2 a hydroplane structurehaving a multlple number vof steps on its bottom arranged in convexformation longitudinally and hav-.

ing the lowernostpoint of convexity located substantially approximatelybelow the cen- -te'r of gravity ofthe machine as a lwhole when the`machine is on a horizontal course.

7 A hydroplaneliying machine comprising an aerial supporting surface,and a hydroplan'e structure connected therewith,

said structure having its hydroplaning sur- I u y ple number ofstepsarranged 1n convex face provided with a multiple number of. stepsarranged 'longitudinally on the arcofa circle having itscenter'approximately in' .the longitudinal vertical plane andapproximately in vertical alinement with the/center of gravity, of themachine as a whole.

In testimony whereof we ax our signatures.

- GLENN H. CURTISS.

JoHN 1P. T Anox.

